Alternate Data Streams in VB6

Hello everyone. Today I'm gonna show you how to use ADS in VB6

At first we need 2 APIs because we can't use common methods for the Windows ADS.

Private Declare Function OpenFile Lib "kernel32" (ByVal lpFileName As String, lpReOpenBuff As OFSTRUCT, ByVal wStyle As Long) As Long
Private Declare Function DeleteFile Lib "kernel32" Alias "DeleteFileA" (ByVal lpFileName As String) As Long

And the used declarations

Private Const OF_EXIST = &H4000
Private Const OFS_MAXPATHNAME = 128
Private Type OFSTRUCT
cBytes As Byte
fFixedDisk As Byte
nErrCode As Integer
Reserved1 As Integer
Reserved2 As Integer
szPathName(OFS_MAXPATHNAME) As Byte
End Type

With these APIs (OpenFile and DeleteFile) we can easily access hidden Files.
Now we need to create a file as an ADS. Here is a code, how to read a File into the memory and then recreate it as an ADS

Dim buffer as string, FilePath as string, NewPath as string
FilePath = "C:\a.txt"
NewPath = "C:\b.txt:a.txt"
Open FilePath For Binary As #1
Open NewPath For Binary As #2
buffer = Space$(LOF(1))
Get #1, , buffer
Put #2, , buffer
Close

In this code the File 'a.txt' with the number #1 is read in the Memory and than it will be recreated as 'b.txt:a.txt'
Now we don't know if the file really exists. With the common 'FileExists' function we can't check it, because the file is hidden.
That's why the API 'OpenFile' will be used.

Here is a code to check if a file exists using the 'OpenFile' API

Public Function FileExists(ByVal Filename As String) As Boolean
Dim OF As OFSTRUCT
FileExists = OpenFile(Filename, OF, OF_EXIST) = 1
End Function

You can save this as a Module or what ever and call it in your code like this

If FileExists(NewPath) = True then
 Call MsgBox("File exists")
End if

To delete a File use this code

Call DeleteFile(newpath)

Now you can easily hide files, such as inis which you need for your program, in the ADS.